The invention relates to a static-dissipative web construction, suitable for example as a floor mat to enable personnel-accumulated static electricity to safely discharge from a person standing on the mat.
Various static-discharge mat constructions have been proposed, ranging from such highly conductive configurations as to permit the hazard of substantially instantaneous discharge, to slow-leaking constructions which exhibit undesirable dependence upon ambient humidity. Between these extremes, U.S. Pat. No. 4,208,696 to Lindsay, et al. describes a multi-layer static-dissipative web wherein an open-weave fabric in the form of cotton scrim is rendered electrically conductive (using carbon in a latex binder) and is interposed between upper and lower layers of relatively low conductivity, to produce mat constructions having an overall volume resistivity between 10.sup.10 and 10.sup.11 ohm-cm and surface resistance in the order of 10.sup.8 ohms per square; Lindsay et al. predicate their results on the foraminous nature of their conductive open-weave fabric. While the Lindsay, et al. product is in many respects satisfactory, it is prone to delamination, and for many applications an order of magnitude reduction in surface resistance is desirable, i.e., to the order of 10.sup.7 ohms per square.